失稳

Included among them are: characteristic frequency curve of reinforced medium; critical length of the anchor bar ; anchor bar density and nonuniform coefficient of the reinforced medium; embedded anchorage layer effect; bed plate effect; weak surface effect; distortion of the bow-shaped distributed state of the anchor bar frictional resistance and initiation, formation and development of the dominant glide control plane; criteria about the displacement velocity of side-wall stability status, critical status and unstability status, and the system of ordinate analysis method, et al

d。文中提出的若干新的概念、判据和分析方法，如加固介质特征频度线；临界锚杆长度；锚杆密度及加固介质不均匀系数；嵌固层效应；垫板效应；弱面效应；锚杆&弓形&受力形态的畸变与优势滑移控制面的产生、形成和发展；边壁稳定状态、临界状态和失稳状态的位移速度判据；纵坐标系分析法等，具有一定的理论价值，并对软土工程围护设计具有指导意义。

Some experiments have been done by simulating in-situ hydrate formation system by gas migrating in seepage system in a glass bubble cell.The phenomena in experiments indicate that gas migration can change the quality of mass and heat transfer of the interface between gas and liguid when hydrate is forming,and it's a moving process of equilibrium curve.There wil...

在鼓泡透明玻璃反应釜里模拟渗漏系统气体穿越多孔隙砂层形成水合物的过程实验，分析了气体迁移对气体水合物形成时气液界面的传质传热性质影响，表明实验中气体迁移形成水合物的过程是一种相平衡曲线动态移动的过程；在形成水合物的气—液界面存在具有一定厚度的过渡层，只要过渡层内气体达到饱和即可形成水合物；气体在迁移中不断形成水合物并在孔隙中形成过压，导致地层骨架的力学破裂和失稳；必须建立一个新的水合物相图以适应气体迁移形成水合物过程的这种新特性。

Current instability of vapor duct is analyzed and the stability of reinforcing ring is check ed.

分析二次蒸汽管失稳现状，校核加强圈设置的稳定性，提出真空设备、管道维护中普遍存在的问题及预防措施。

A simplified mechanical model of a typical axially loaded sleeved compression member is introduced. Some reasonable constitutive relation curves of the inner steel tube are chosen for analyzing in two numerical examples. One is analysis on its axially loaded bearing capacity under different working conditions. The other is stability analysis of grid structure with SCM. The buckling control effect of the inner steel tube is evaluated with the outer steel tube applied in these conditions.

阐述了轴心受压情况下典型套管构件的简化力学模型，选择利用合理的套管构件内核本构关系，用2个算例（内核圆钢管不同工况下的轴压承载力分析和网架结构应用套管构件的稳定计算分析）分析了外钢管对轴心受压内钢管的失稳控制效果。

Based on the relations among the stress, final wall-thickness of thin-walled tube and the characteristics of tube material, original size, curling radius along with friction condition in a axially-compressed internal inversion process on right-angled fillet die, some analytical discriminants were established for judging if a double-layered tubular piece of aluminum alloy could be steadily formed from a certain-sized round tube via internal inversion process without interference and plastic instability of tube wall, and a method was put forward for determining the maximum and minimum usable curling radius or die fillet-radius for thin-walled tubes in the process.

基于薄壁管直角圆角模轴压内翻过程中各处应力及最终壁厚与管材特性、管坯尺寸、卷曲半径及摩擦条件之间的关系，推出了判别任一铝合金双层管件可否由特定尺寸圆管稳定内翻成形而不出现管壁干涉与塑性失稳问题的解析判别式，指出了确定薄壁管圆角模内翻卷曲半径或模具圆角半径极限值的方法。

Some rock slopes with different combination of joints varying in number andcut-through ratio, The influence of cut-through ration, position and combination form ofjoints on slope failure mode is discussed.

计算分析了含单一及多组节理、贯通及非贯通节理不同组合时岩体边坡的失稳规律，论了节理存在分布对岩体边坡稳定性的影响。

The result accords with surrounding rock of practical construction, it not only offers references for preventing instability and failure of deep-buried tunnels, but also gives an important guidance for reasonable construction technique of supporting measures.

研究成果可为预防深埋隧道围岩失稳、采取合理的施工工艺和支护措施提供参考依据。

Dump truck has a propensity to roll over in certain situations. Variable soil conditions, high winds, significant ground slope, and shifting loads contribute to a high risk of rollover for dump trucks, In this study, a dynamic simulation model of a dump truck with triangle rod assembly lifting mechanism was established to study the dumping stability of the dump truck. Through the dynamic simulation of the dump truck model in several typical situations, the dynamic rollover threshold values were determined.

本文主要针对自卸汽车在作业卸载时容易失稳发生侧翻的现象，以某厂三角臂组合式举升机构的自卸汽车为研究对象，建立自卸汽车整车虚拟样机模型，综合考虑影响自卸汽车作业稳定性的各种主要因素，对自卸汽车的作业稳定性进行仿真分析，找出了自卸汽车侧翻的临界值。

Only with such characteristics, the movement equations can be expressed as matrices, and the idea of transforming the movement equations to the simplest form through a nonlinear transformation can be realized;(2) The form of Zi =Yi + YTH2i Y + Y7H3i Y(2)+ Y(2)T H4i Y(2)+ YTH5i Y(3) is adhibited in the nonlinear transformation, so that the multivalued problem caused by the nonlinear transformation is avoided, and the higher order transformation can be taken next;(3) The fourth order nonlinear transformation matrices H21,H31,H41 and H51 are derived, by which the original movement equations of electric power system is transformed to Jodan form in Z space;(4) By use of the fourth order nonlinear transformation, the approximate expression of the stability boundary is obtained, in Z space it is Z1= 0,in Y space it is Y1 + YTH21 Y + YTH31 Y(2)-i- Y(2) TH41 Y(2)+YTH51 Y(3)= 0;(5) The criterion used in this paper to judge whether the system critical unstable is simple and quick;(6) The method used in this paper is a direct method, and no need to construct an energy function.

正是由 于电力系统的运动方程具有这样的特性，才能写成矩阵的形式，通过非线性变换将电力系统的运动方程变换为最简单的线性形式的思想才能得以实现；（2）将通常运用于电力系统暂态稳定性分析的Normal Form变换的形式由 Yi＝ Zi＋ ZTh2riZ变形为 Zi＝ Yi＋YTH2iY＋YTH3iY（2）＋Y（2）TH4iY（2）＋YTH5iY（3），从而使得在对持续故障轨线实施同样的非线性变换以确定临界切除时间时，避免了非线性变换带来的多值性的问题，而只有在没有多值性问题的困扰下，才能采用较高阶的变换：（3）推导出了将原始电力系统系统的运动方程变换到Z空间的约当形式的非线性变换矩阵H21、H31、H41、HS1：（4）在运用四阶了「线性变换的情况下，给出了受扰动后系统的稳定边界的近似的解析表达，在Z空间为Z1=0，在y空间为： Y1+YTH21Y+YTH31Y(2)+Y(2)TH41Y(2)+YTH51Y(3)=0 （5）确定临界失稳的判据简单、快捷：对于一个复杂的电力系统，其稳定边界是相当复杂的一个高维曲面，即便是已知系统稳定边界的解析表达，要求出系统持续故障轨线何时与这一高维曲面相交，在数学上几乎是不可能实现的。

Research on local scour during settling of steel caissons is an important topic for design and construction of large-scaled bridge piers.

钢沉井下沉过程中局部冲刷的研究是同类桥墩设计和施工十分关心的重要课题，它对保证钢沉井安全有效施工、桥梁设计中施工期桥墩最大冲深、失稳和安全计算有重要参考价值。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。